http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/293 2026-04-20T13:52:02Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/308 Studies on molecular characterisation and phylogenetic analysis of dragonflies and damselflies (Odonata: Insecta) of selected habitats of Kerala Nitha Bose C; Francy K Kakkassery; Binoy CF Odonata is a primitive order of class Insecta. The order is divided into three suborders- Anisoptera, Zygoptera and Anisozygoptera. Anisoptera is the suborder of dragonflies and damselflies belonging to the suborder Zygoptera. Anisozygoptera is a living fossil and has only 3 species representatives globally. Odonates are hemimetabolous insects and both larval and adult forms are predators. They are amphibiotic; egg and larval development take place in water and adults are aerial. Odonates are naturally considered as biocontrol agents and bioindicators. Various habitats of high land, midland and low land regions of 5 districts of Kerala were selected for the study. A total of 73 locations were observed in the Thrissur, Ernakulam, Palakkad, Wayanad and Idukki districts of Kerala. The observed habitats include streams, rivers, ponds, lakes, paddy fields, ditches and estuaries. A total of 71 species (33 species of damselflies and 38 species of dragonflies) were observed during the study. They belong to 10 families and 43 genera. The Western Ghats endemic species recorded during the work were Aciagrion approximans krishna, Agriocnemis keralensis, Pseudagrion indicum and Protosticta gravelyi. The rarely found species Paracercion malayanum is the first record from central and northern Kerala. Taxonomic keys for the observed 71 species of odonates were prepared. Traditionally organisms were classified based on morphological features. Many research workers pointed out the limitations of traditional taxonomy. These challenges can be overcome by molecular taxonomic approaches. The results of phylogenetic analysis become more convincing when multiple marker genes are included in the study. So, the present work focused on mitochondrial COI gene and nuclear 18S rRNA gene for the molecular characterisation and phylogenetic assessment of selected odonates of Kerala. Molecular characterisation of 34 species belonging to 28 genera was done. Partial COI gene, 18S rRNA gene sequences and translated protein sequences were generated. Of these, twelve COI gene sequences and twenty three 18S rRNA gene sequences are the first worldwide GenBank records. Mitochondrial COI sequences can be used for precise and faster identification of odonate species and phylogenetic studies. Nuclear 18S rRNA gene sequences are beneficial in higher level phylogenetic analysis. Phylogenetic analyses of two suborders and selected families, based on partial COI and 18S rRNA gene sequences were carried out and genetic divergence values among odonates were estimated. The efficiency of partial COI and 18S rRNA marker genes in resolving relationships was studied. A detailed comparison of trees based on both marker genes revealed the efficiency of COI over the 18S rRNA gene in resolving family and suborder trees. Phylogenetic analyses of the 27 genera were done based on COI gene sequences. The results of the analyses and the calculated genetic divergence values provided insights into intraspecific and interspecific genetic variation of odonates across large geographic distances. The majority of odonates selected for the study showed low genetic variability over long distances (different countries and continents) except for eight species. When comparing the results, genetic variability was lesser in damselflies and considerably high in dragonflies. The estimated interspecific divergence values within each genus showed that maximum and minimum interspecific divergence values were possessed by genus Tholymis and genus Dysphaea respectively. Another finding of the study was the close genetic similarity observed between morphologically dissimilar and geographically distant species. 2023-04-01T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/296 Studies on the life history of blow flies (Diptera: Calliphoridae) in central Kerala and its forensic significance Reject Paul MP; Binoy CF The flies belonging to the Diptera, Calliphoridae are the first visitors to inhabit and colonize the dead body within a short period of time of cadavers found. The importance of generating location specific data of forensically important blow fly species for accurate assessment of PMI was evident from the previous works. The present investigation has recorded 17 blow fly species belonging to 4 subfamilies and 8 genera from central Kerala. In this study four forensically significant blow flies; Chrysomya megacephala, Chrysomya rufifacies, Chrysomya chani and Hemipyrellia ligurriens were identified based on their morphological and molecular characteristics. Seasonal abundance of blow flies were found to be significantly higher in monsoon. Morphology of egg, larval instars and pupa were studied. The ultra structural details of larval instars were analyzed using Scanning Electron Microscopy (SEM). Life cycle parameters like fecundity, length and weight of larval instars and duration of life of eggs, different larval instars and pupation were studied. The survival rate (%) in the different life stages were studied and it was found that higher survival rate was seen in the egg and instar I. Effect of temperature and humidity on the life cycle of blow flies was investigated and it showed that the pre-oviposition period was significantly higher in winter in all the four species. The number of eggs laid in a day and during the life span by all species were significantly higher in monsoon. The periodicity of egg laying was significantly higher in winter for all species. The time dependent growth data corresponding to the length and weight of larval instars of blow flies during different seasons were investigated and found that the length and weight was significantly higher in monsoon for C. megacephala and C. rufifacies and in summer for C. chani and H. ligurriens. The total duration taken by the fly for its development from the egg stage till the emergence of adult fly was shorter in summer, followed by monsoon and winter. Comparative studies of laboratory rearing of the four species with the outdoor rearing results showed that the developmental duration of different stages in the outdoor rearing were higher. The survival rate of all species were found to be significantly higher in monsoon in comparison to other seasons. The major outcome of this study is that the results of outdoor rearing cannot be simulated in the laboratory. A high value of coefficient of determination (R2) was obtained for all the four blow fly species for the predicted regression equation which indicated that higher percent of variability in larval length can be explained by duration. The regression equation method developed in this study emerged as the best suitable method for the estimation of PMI using life history of the blow flies. The changes observed in the rate of developmental data of the blow flies might be due to the changes in humidity, rainfall and temperature prevailing in the geographically different areas and genetic variations of blow flies. This cautions that while performing the assessment of PMI, the investigators should be very careful about the climatic conditions prevailing in the respective study area and signifies the importance of generating location specific data of forensically important species of blow flies. This is the first report on the developmental rate of these blow fly species during different seasons from South India. Present investigation on the life cycle of above mentioned blow flies and the regression equation model constructed for the PMI assessment of dead bodies has been found to be useful for application in forensic investigations in the study region. Further research can be conducted to augment the present study results and for exploring new dimensions in future. 2023-07-01T00:00:00Z